release/src-rt-6.x.4708/linux/linux-2.6.36/arch/um/kernel/um_arch.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <linux/delay.h>
   7 #include <linux/init.h>
   8 #include <linux/mm.h>
   9 #include <linux/module.h>
  10 #include <linux/seq_file.h>
  11 #include <linux/string.h>
  12 #include <linux/utsname.h>
  13 #include <asm/pgtable.h>
  14 #include <asm/processor.h>
  15 #include <asm/setup.h>
  16 #include "as-layout.h"
  17 #include "arch.h"
  18 #include "init.h"
  19 #include "kern.h"
  20 #include "kern_util.h"
  21 #include "mem_user.h"
  22 #include "os.h"
  23
  24 #define DEFAULT_COMMAND_LINE "root=98:0"
  25
  26 /* Changed in add_arg and setup_arch, which run before SMP is started */
  27 static char __initdata command_line[COMMAND_LINE_SIZE] = { 0 };
  28
  29 static void __init add_arg(char *arg)
  30 {
  31         if (strlen(command_line) + strlen(arg) + 1 > COMMAND_LINE_SIZE) {
  32                 printf("add_arg: Too many command line arguments!\n");
  33                 exit(1);
  34         }
  35         if (strlen(command_line) > 0)
  36                 strcat(command_line, " ");
  37         strcat(command_line, arg);
  38 }
  39
  40 struct cpuinfo_um boot_cpu_data = {
  41         .loops_per_jiffy        = 0,
  42         .ipi_pipe               = { -1, -1 }
  43 };
  44
  45 unsigned long thread_saved_pc(struct task_struct *task)
  46 {
  47         return os_process_pc(userspace_pid[0]);
  48 }
  49
  50 /* Changed in setup_arch, which is called in early boot */
  51 static char host_info[(__NEW_UTS_LEN + 1) * 5];
  52
  53 static int show_cpuinfo(struct seq_file *m, void *v)
  54 {
  55         int index = 0;
  56
  57 #ifdef CONFIG_SMP
  58         index = (struct cpuinfo_um *) v - cpu_data;
  59         if (!cpu_online(index))
  60                 return 0;
  61 #endif
  62
  63         seq_printf(m, "processor\t: %d\n", index);
  64         seq_printf(m, "vendor_id\t: User Mode Linux\n");
  65         seq_printf(m, "model name\t: UML\n");
  66         seq_printf(m, "mode\t\t: skas\n");
  67         seq_printf(m, "host\t\t: %s\n", host_info);
  68         seq_printf(m, "bogomips\t: %lu.%02lu\n\n",
  69                    loops_per_jiffy/(500000/HZ),
  70                    (loops_per_jiffy/(5000/HZ)) % 100);
  71
  72         return 0;
  73 }
  74
  75 static void *c_start(struct seq_file *m, loff_t *pos)
  76 {
  77         return *pos < NR_CPUS ? cpu_data + *pos : NULL;
  78 }
  79
  80 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
  81 {
  82         ++*pos;
  83         return c_start(m, pos);
  84 }
  85
  86 static void c_stop(struct seq_file *m, void *v)
  87 {
  88 }
  89
  90 const struct seq_operations cpuinfo_op = {
  91         .start  = c_start,
  92         .next   = c_next,
  93         .stop   = c_stop,
  94         .show   = show_cpuinfo,
  95 };
  96
  97 /* Set in linux_main */
  98 unsigned long uml_physmem;
  99 unsigned long uml_reserved; /* Also modified in mem_init */
 100 unsigned long start_vm;
 101 unsigned long end_vm;
 102
 103 /* Set in uml_ncpus_setup */
 104 int ncpus = 1;
 105
 106 /* Set in early boot */
 107 static int have_root __initdata = 0;
 108
 109 /* Set in uml_mem_setup and modified in linux_main */
 110 long long physmem_size = 32 * 1024 * 1024;
 111
 112 static const char *usage_string =
 113 "User Mode Linux v%s\n"
 114 "       available at http://user-mode-linux.sourceforge.net/\n\n";
 115
 116 static int __init uml_version_setup(char *line, int *add)
 117 {
 118         printf("%s\n", init_utsname()->release);
 119         exit(0);
 120
 121         return 0;
 122 }
 123
 124 __uml_setup("--version", uml_version_setup,
 125 "--version\n"
 126 "    Prints the version number of the kernel.\n\n"
 127 );
 128
 129 static int __init uml_root_setup(char *line, int *add)
 130 {
 131         have_root = 1;
 132         return 0;
 133 }
 134
 135 __uml_setup("root=", uml_root_setup,
 136 "root=<file containing the root fs>\n"
 137 "    This is actually used by the generic kernel in exactly the same\n"
 138 "    way as in any other kernel. If you configure a number of block\n"
 139 "    devices and want to boot off something other than ubd0, you \n"
 140 "    would use something like:\n"
 141 "        root=/dev/ubd5\n\n"
 142 );
 143
 144 static int __init no_skas_debug_setup(char *line, int *add)
 145 {
 146         printf("'debug' is not necessary to gdb UML in skas mode - run \n");
 147         printf("'gdb linux'\n");
 148
 149         return 0;
 150 }
 151
 152 __uml_setup("debug", no_skas_debug_setup,
 153 "debug\n"
 154 "    this flag is not needed to run gdb on UML in skas mode\n\n"
 155 );
 156
 157 #ifdef CONFIG_SMP
 158 static int __init uml_ncpus_setup(char *line, int *add)
 159 {
 160         if (!sscanf(line, "%d", &ncpus)) {
 161                 printf("Couldn't parse [%s]\n", line);
 162                 return -1;
 163         }
 164
 165         return 0;
 166 }
 167
 168 __uml_setup("ncpus=", uml_ncpus_setup,
 169 "ncpus=<# of desired CPUs>\n"
 170 "    This tells an SMP kernel how many virtual processors to start.\n\n"
 171 );
 172 #endif
 173
 174 static int __init Usage(char *line, int *add)
 175 {
 176         const char **p;
 177
 178         printf(usage_string, init_utsname()->release);
 179         p = &__uml_help_start;
 180         while (p < &__uml_help_end) {
 181                 printf("%s", *p);
 182                 p++;
 183         }
 184         exit(0);
 185         return 0;
 186 }
 187
 188 __uml_setup("--help", Usage,
 189 "--help\n"
 190 "    Prints this message.\n\n"
 191 );
 192
 193 static void __init uml_checksetup(char *line, int *add)
 194 {
 195         struct uml_param *p;
 196
 197         p = &__uml_setup_start;
 198         while (p < &__uml_setup_end) {
 199                 size_t n;
 200
 201                 n = strlen(p->str);
 202                 if (!strncmp(line, p->str, n) && p->setup_func(line + n, add))
 203                         return;
 204                 p++;
 205         }
 206 }
 207
 208 static void __init uml_postsetup(void)
 209 {
 210         initcall_t *p;
 211
 212         p = &__uml_postsetup_start;
 213         while (p < &__uml_postsetup_end) {
 214                 (*p)();
 215                 p++;
 216         }
 217         return;
 218 }
 219
 220 static int panic_exit(struct notifier_block *self, unsigned long unused1,
 221                       void *unused2)
 222 {
 223         bust_spinlocks(1);
 224         show_regs(&(current->thread.regs));
 225         bust_spinlocks(0);
 226         uml_exitcode = 1;
 227         os_dump_core();
 228         return 0;
 229 }
 230
 231 static struct notifier_block panic_exit_notifier = {
 232         .notifier_call          = panic_exit,
 233         .next                   = NULL,
 234         .priority               = 0
 235 };
 236
 237 /* Set during early boot */
 238 unsigned long task_size;
 239 EXPORT_SYMBOL(task_size);
 240
 241 unsigned long host_task_size;
 242
 243 unsigned long brk_start;
 244 unsigned long end_iomem;
 245 EXPORT_SYMBOL(end_iomem);
 246
 247 #define MIN_VMALLOC (32 * 1024 * 1024)
 248
 249 extern char __binary_start;
 250
 251 int __init linux_main(int argc, char **argv)
 252 {
 253         unsigned long avail, diff;
 254         unsigned long virtmem_size, max_physmem;
 255         unsigned long stack;
 256         unsigned int i;
 257         int add;
 258         char * mode;
 259
 260         for (i = 1; i < argc; i++) {
 261                 if ((i == 1) && (argv[i][0] == ' '))
 262                         continue;
 263                 add = 1;
 264                 uml_checksetup(argv[i], &add);
 265                 if (add)
 266                         add_arg(argv[i]);
 267         }
 268         if (have_root == 0)
 269                 add_arg(DEFAULT_COMMAND_LINE);
 270
 271         host_task_size = os_get_top_address();
 272         /*
 273          * TASK_SIZE needs to be PGDIR_SIZE aligned or else exit_mmap craps
 274          * out
 275          */
 276         task_size = host_task_size & PGDIR_MASK;
 277
 278         /* OS sanity checks that need to happen before the kernel runs */
 279         os_early_checks();
 280
 281         can_do_skas();
 282
 283         if (proc_mm && ptrace_faultinfo)
 284                 mode = "SKAS3";
 285         else
 286                 mode = "SKAS0";
 287
 288         printf("UML running in %s mode\n", mode);
 289
 290         brk_start = (unsigned long) sbrk(0);
 291
 292         /*
 293          * Increase physical memory size for exec-shield users
 294          * so they actually get what they asked for. This should
 295          * add zero for non-exec shield users
 296          */
 297
 298         diff = UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 299         if (diff > 1024 * 1024) {
 300                 printf("Adding %ld bytes to physical memory to account for "
 301                        "exec-shield gap\n", diff);
 302                 physmem_size += UML_ROUND_UP(brk_start) - UML_ROUND_UP(&_end);
 303         }
 304
 305         uml_physmem = (unsigned long) &__binary_start & PAGE_MASK;
 306
 307         /* Reserve up to 4M after the current brk */
 308         uml_reserved = ROUND_4M(brk_start) + (1 << 22);
 309
 310         setup_machinename(init_utsname()->machine);
 311
 312         highmem = 0;
 313         iomem_size = (iomem_size + PAGE_SIZE - 1) & PAGE_MASK;
 314         max_physmem = TASK_SIZE - uml_physmem - iomem_size - MIN_VMALLOC;
 315
 316         /*
 317          * Zones have to begin on a 1 << MAX_ORDER page boundary,
 318          * so this makes sure that's true for highmem
 319          */
 320         max_physmem &= ~((1 << (PAGE_SHIFT + MAX_ORDER)) - 1);
 321         if (physmem_size + iomem_size > max_physmem) {
 322                 highmem = physmem_size + iomem_size - max_physmem;
 323                 physmem_size -= highmem;
 324 #ifndef CONFIG_HIGHMEM
 325                 highmem = 0;
 326                 printf("CONFIG_HIGHMEM not enabled - physical memory shrunk "
 327                        "to %Lu bytes\n", physmem_size);
 328 #endif
 329         }
 330
 331         high_physmem = uml_physmem + physmem_size;
 332         end_iomem = high_physmem + iomem_size;
 333         high_memory = (void *) end_iomem;
 334
 335         start_vm = VMALLOC_START;
 336
 337         setup_physmem(uml_physmem, uml_reserved, physmem_size, highmem);
 338         if (init_maps(physmem_size, iomem_size, highmem)) {
 339                 printf("Failed to allocate mem_map for %Lu bytes of physical "
 340                        "memory and %Lu bytes of highmem\n", physmem_size,
 341                        highmem);
 342                 exit(1);
 343         }
 344
 345         virtmem_size = physmem_size;
 346         stack = (unsigned long) argv;
 347         stack &= ~(1024 * 1024 - 1);
 348         avail = stack - start_vm;
 349         if (physmem_size > avail)
 350                 virtmem_size = avail;
 351         end_vm = start_vm + virtmem_size;
 352
 353         if (virtmem_size < physmem_size)
 354                 printf("Kernel virtual memory size shrunk to %lu bytes\n",
 355                        virtmem_size);
 356
 357         atomic_notifier_chain_register(&panic_notifier_list,
 358                                        &panic_exit_notifier);
 359
 360         uml_postsetup();
 361
 362         stack_protections((unsigned long) &init_thread_info);
 363         os_flush_stdout();
 364
 365         return start_uml();
 366 }
 367
 368 void __init setup_arch(char **cmdline_p)
 369 {
 370         paging_init();
 371         strlcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
 372         *cmdline_p = command_line;
 373         setup_hostinfo(host_info, sizeof host_info);
 374 }
 375
 376 void __init check_bugs(void)
 377 {
 378         arch_check_bugs();
 379         os_check_bugs();
 380 }
 381
 382 void apply_alternatives(struct alt_instr *start, struct alt_instr *end)
 383 {
 384 }
 385
 386 #ifdef CONFIG_SMP
 387 void alternatives_smp_module_add(struct module *mod, char *name,
 388                                  void *locks, void *locks_end,
 389                                  void *text,  void *text_end)
 390 {
 391 }
 392
 393 void alternatives_smp_module_del(struct module *mod)
 394 {
 395 }
 396 #endif